Complete the paragraphs with the correct form of the words and expressions in the box.

ancestor       scientific       be native to       primitive habitat       appearance       be home to       ecosystem

【小题1】The Galapagos Islands are renowned worldwide for their unique biodiversity. The Giant Tortoise Reserve on Santa Cruz ________ several species of giant tortoise that ________ the Galapagos Islands. The island is also home to the Charles Darwin Research Station, where ________ studies are carried out.
【小题2】Mangroves are one of the coastal plants that grow on Isabela. They serve as the ________ for various birds and fish, and are very important to the ________.
【小题3】Iguanas can be found on San Cristobal. They have a very special ________, with comb-like spines on their back. There is evidence that all the different iguanas have developed from more ________ ones and share a common ________.